hidden



C. P. HIDDEN.

CARRIER DESPATCH APPARATUS. APPLICATION FILED FEB. 27, 1914.

1,3 1 1 ,%'7. Patented July 29, 1919.

2 SHEETS-SHEET l.

THE COLUMBIA PLANOGRAPH 60.. WASHINGTON. D. c.

C. P. HIDDEN.

CARRIER DESPATCH APPARATUS.

APPLICATION FILED FEB. 27. 1914.

2 SHEETSSHEET 2.

THE COLUMBIA PLANOGRAPH c0., WASHINGTON. D. c.

UNITED srarrnls (PATENT ornron.

CHARLES P. HIDDEN, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR. TO THE LAMSON' COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF vNEW JERSEY.

CARRIER-DESPATCH APPARATUS.

To all whom it may concern:

Be it known that I, CHARLEs P. HIDDEN, a citizen of the United States, residing at Brookline, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Carrier-Despatch Apparatus, of which the following is a specification.

This invention relates to carrier despatch systems in general and more especially to pneumatic despatch tube apparatus. It has for its principal object the economization of power by novel means; but further aims, while so doing, to insure eflilcient service and to avoid delays in the despatch and transmission of carriers.

Another object of my invention is to enable the use, in one aspect of'the invention, of an open tube in pneumatic despatch systems while utilizing an interference with a slight normal flow of air through the tube, due for example, to the insertion of a carrier, to open a valve or actuate some suitable instrumentality whereby to establish a carrier transmitting flow of air through said tube; and to normally balance or counteract the effect of this relatively heavy flow of air and consequent change in the pressure conditions acting upon said instrumentality, preferably, but, as I shall show, not necessarily directly upon the emergence of the carrier from the tube.

A further object has been to provide a means for automatically discontinuing an expenditure of power in a despatch system after such power is no longer needed; said means being actuated periodically or at recurrent intervals.

These and a number of other objects of my invention will be hereinafter referred to and the novel elements and combinations of elements whereby said objects may be attained will be more particularly pointed out in the claims appended hereto. 7

In the accompanying drawings which form parts thereof and in which like reference characters designate like parts throughout the respective views, I have exemplified certain preferred constructions; but as I am aware that various changes and omissions or substitutions of parts or instrumentalities may be made herein without departing from the spirit of my invention ,I desire to be limited only by the scope of said claims.

Referring to the drawings:

Specification of Letters Patent.

Patented July 29, 1919.

Application filed February 27, 1914. Serial No. 821,534.

Figure 1 is a somewhat diagrammatic representation of a pneumatic despatch system embodying my invention.

Fig. 2 is a front elevation, drawn to a larger scale and partly broken away, of a part of said apparatus, hereinafter referred to as a breathing tube. V

Fig. 3 is a transverse section taken on line III-III of Fig. 2.

Fig. 4 is a view partly in elevation and partly in vertical or longitudinal section, of a valve which controls the flow of air through the transmission tube; the casing of said valve being shown adjacent said breathing tube in Fig. 1.

Fig. 5 is a detail view of the periodic circuit maker or recurrently acting timing device hereinafter referred to.

Fig. 6 is a diagrammatic detail represencation of a contact making solenoid and its diaphragm dashpot also hereinafter referred to.

Fig. 7 is a detail, vertical, median section of the valve which controls the counter-acting sensitive apparatus; the sectioned valve being viewed from the opposite side to that shown in Fig. 1.

Fig. 8 is a view similar to Fig. 1 of a modification of the system.

"Fig. 9 is an enlarged detail view of certain controlling parts shown in Fig. 8.

In the construction in Fig. 1 but two stations have been indicated, namely-stations A and B; but it is obvious of course that the invention is not to be regarded as being limited to any particular number of stations or tubes or other transmission media.

The tube for idespatching carriers from station A to station B, designated 1, is preferably open at station A, and delivers to a terminal 2 of a type commonly in use; the aperture at which carriers emerge at station B being normally closed by a valve 3.

The tube, shown by way of eXeInplification, for returning carriers from station E to station A, and designated 4:, isprovided with the usual receiving terminal 5 closed by a'clapper'valve 6; and communication is afforded between tubes 1 and 4 through a suitable. conduit 7 provided at the base of the delivery terminal 2. Carriers traversing tube 4: are delivered to a shelf or receiving terminal 8 past a clapper valve 9; and the air passes laterally from tube 4, adjacent valve 9, through a conduit 10 to such a sytem except where in certain of the claims it is specifically so indicated that such claims are to be so limited.

Returning to the description ofthe apparatus shown in Fig. 1, the drum 12 is connected to a'suitable blower or pump 13- which may be driven by an electric motor 14 by means, for example, of a'belt 15. Be tween the tube 11 and the drum 12 is disposed a valve casing 16, the valve 17of which controls the flow of air through the transit tubes to said, drum. This valve has,

been drawn to a relatively large scale in Fig. 4 and as valves of this particular type are 'in common use but brief description need be given of the same herein- Valve 17 is pivoted at 18'and is normally held'against' its seat by the pressure of the air thereabove resulting from the partial vacuum in the connection 19 between the valve casing'and thedrum. A light spring 20 also normally urges this valve to its closed position. v

Connected to the underside of the valve'is a link 21-, the right hand end of which, as

' viewed in Fig. 4, is attached to a diaphragm the casing 1'6'being recessed to provide a chamber 24 to the right of the diaphragm, said chamber being in communication with the tube 19 and space below the valve, through a conduit 25. The ffiow of air through this conduit is, however, restricted by a ne edle'or timing valve26. To one side of the chamber 24 is a port 27 which communicatesf'with the outer air when a' pilot valve 28is' in its raisedposition. This valve is controlled by a solenoid 29 which will be hereinafter referred to. 7

I also prefer to provide a by-pass 30 around the valve 17 and a" valve 31 in this by-pass enables the leakage of air around the valve to be adjusted to a nicety.

Immediately above the casing 16 is a T 32t0 which is connected a pipe 33 which leads to a construction 34 which I have termed a breathing tube. v I This apparatus has been shown in detail in Figs. 2 and 3 as preferably comprising a tube-like structure, the four walls of which have 'thin but relatively rigid plates or panels 35 in the centers thereof; these panels being preferably pivoted at their upper edges as at 36.

Thepanels may be made of light sheet metal flanged at' their edges, as at 35, for stiffness and also to afford means ferretaining the edges of the sheet con-.

nections 37 in place thereon-.- The latter are preferably of relatively impervious flexible material such as rubber-impregnated canvas 7 or the likeand are creased or folded bellows pivotally connected links or toggles 40.

These latter may extend upwardly at about 4'5? angles as indicated in- Fig. 2, and have their upper extremities pivotally connected as at 41 to a spideror frame 42. The latter is recessed for the'reception of and is rigidly connected to a rod 43 which extends down through the hub of the plate 38; being adapted for movement through the latter but fitting the walls of the orifice throughwhich it moves sufficiently closely to prevent any material ingress of air.

Below rod 43 is: a second and inverted breathing tube 44, or some equivalent device, preferably "having a slightly less effective surface than apparatus 7 34, but adapted tooppose the action of said' breathing tube or sensitive apparatus to a determined extent under conditions hereinafter set forth The rod 43 between the sensitive apparatus 34 and 44 hasthereon'a collar 45 to which is attached the upper extremity off'a' spring 46 disposed around'said rod; the lower end of spring 46 bearing againstthe' hub'of' the plate 47 which'corres aonds-to plate 38' of apparatus 34. Plat'et'l in turnis carried by a bracket 47. upon rod '43 i'sfa contact plate 48, which is moved up'an'ddown by said rod between pairs of contacts 49 and 50. v I preferably also'provide a turn bu'ckle5 in the r0d43'whereby the overall lengthof the'lattermaybe adjusted; I It will be evident from the above descrip tion that when thewalls or panels'35 are caused to approach each other, rod 43 will be lifted'by reason of the toggle action of the links40'and will thereby lift the contact plate48 into engagement with the contacts 50; while when the breathing tube is distended, or in'other words, when'its walls are caused to move apart, contact plate 48 will be correspondingly driven downwardly into engagement with contacts 49; p i

'The spring 46 is adjusted so that under normal conditions, hereinafter referred to, it will tend to position the plate48 midway Also adjustably' mounted between the respective pairs of contacts 49 and 5 0 and the several adjustments noted permit of this disposition of said plate 48 to be effected quite accurately.

It may be here noted that the distance which plate 48 moves in either direction from its median position toward one or the other of said pairs of contacts is but slight; being preferably about one quarter to one half of an inch. A The contacts 49 and 50 are in parallel and the movement of plate 48 into engagement with either pair of these contacts simply completes the same circuit. This circuit is as follows:

The wire 52, for example, is connected to a suitable source of current and has connected thereto a wire 53 which leads to a solenoid 54 or the like. A wire 55 extends from solenoid 54 to the contacts 49 and 50 above referred to; the end of wire 55 being branched and one branch being connected to the left hand contact 50 and the other branch to the. lefthand contact 49. A correspondingly branched wire 56 connects the right hand contacts 49 and 50 with a wire 57, which, in the present instance constitutes the negative lead. When this circuit is energized the solenoid54 lifts .its contact bar 58 and closes a second circuit across contacts 59.

A wire 60 connects the left hand contact 59, as shown in Fig. 1, with the normally energized wire 53 while a wire 61 connects the right hand contact 59 with the solenoid 29 above referred to. Thecurrent leaves the solenoid 29 via wire 62 which connects with the negative lead 57. Contacts 59 are preferably spring contacts and when the plate or bar 58 is lifted into engagement therewith it passes upwardly thereover for some distance.

Connected to the core of solenoid 54 and beneath the latter, as shown in Figs. 1 and 6, is a diaphragm 63 in a casing 64 provided witha timing valve 65 and inlet or check valve 66 in the lower portion of said casing; so that the diaphragm may be freely lifted by the solenoid to bring contact bar 58 into engagement with spring contacts 59; but thereafter when solenoid 54 is deenergized the descent of its core and consequently of contact 58 out of engagement with contacts 59, is slightly retarded the air sucked in through the check valve 66 being more or less slowly expelled through the valve 65 by the weight of said core. As a matter of fact this construction is merely for the purpose of preventing an immediate separation of .contacts 58 and 59 upon the deenergization of-solenoid 54 and" usually serves to maintain the connection between wires 60 and 61 aftersaid deenergization of solenoid 54, for perhaps a second or two; although a longer interval may obviously beprovided if ,found necessary.

The maintenance of the circuit through wire 61 and solenoid 29 for this determined interval insures the maintenance 'of valve 28 in its open position for alike period and of course when this valve is raised air rushes into the chamber 24 and presses diaphragm 22 to the left, as shown in Fig. 4, which opens the main air valve 17 and places the transmission tubes in free'communication with the vacuum drum 12. WVhen valve 28 is allowed to close, the air confined in chamber 24 thereafter slowly escapes through the timing conduit 25 and permits of the closure of valve 17 at a determined rate, which may be, for example, two or three seconds.

Referring again to Fig. 1, it will be noted, that at stations A and B small switches 67 and 68 are connected to the spindles of the valves 9 and 3 respectively, so that when either of these valves is opened by the emergence of, a carrier therethrough its corresponding switch 67 or 68, as the case may be, will respectively engage the corresponding contacts 69 or 70. The latter is directly con nected to the positive lead 52 by a wire 71, while its switch 68 is connected by a wire 72 to a wire 73 which runs from the contact 69 to a contact 74 on the valve casing 16.

The stem of valve 17 carries a contact arm 75, which when this valve is wide open or nearly so, is in engagement with said con tact 74. Current at such time is hence free to flow from contact 74 via switch arm 75 to a wire 76 and thence through a solenoid 77 to negative lead 57. g

The solenoid 77, however, in place of actuating an electrical switch is connected to the actuating lever 7 8 of a small valve 78 which is disposed in a pipe 79 which leads from the upper portionof the apparatus 44, above referred to, preferably directly to the drum .12.

WVhen, therefore, solenoid 77 is energized, as it normally is upon the emergence of a carrier at either station, since switch 67 is also connected to the positive lead 52 by a wire 80, valve 78 will be opened, and, owing to the provision of the latching mechanism now to be described, said valve will not be immediately closed upon the deenergization of said solenoid.

Connected to the switch arm 75 is an arm 81 which when nearing its lowermost position engages the arm 82 of a latch 83 which en ages a hook 84 carried by the lever 7 8 of immediately exhausted from the chamber in exert against said Walls when said valve 17 the casewhen valve 17 is closed, a,

is closed. In other words, While the pressure in the breathing tube is but very little different from that of the atmosphere, as is ronounced vacuum is established in the breiithing tube the moment that the main air inlet valve is opened and were it not for the pro vision of the balancing'mechanism shown, or some equivalent thereof, or of some other means for counteracting this greatly increased effort, contact plate 48 would be maintained in engagement with contacts 50 indefinitely and under the wiring conditions shown valve 17 never would close and hence there would be no further saving of power when said valve was once opened. When valve 78 is closed, the partial vacuum in apparatus 44 is at once relieved by an inrush of airthrough passage in said valve which communicates with the throttling valve 86, as shown ig. 7. I

One otherfeature remains to be considered before the general operation of the mechanism in question is discussed. Above the 'motor 14, in Fig. 1', is box or casing 87 which, asshown in Fig. 5, has mounted upon a'shaft SS therein a Contact arm 89 which when rotated, ,for example, clockwise is adapted-to periodically engage'contacts- 90. One of these isconneoted to the wire 7 3 by a-wire 91- and the :other to the wire 52. The shaft 88is driven in the present case by a worm and wheel gear fromjthe motor; one worm 92 on the motor shaft engaging wheel 93, and the shaft 94 of the latter'carrying a Worm 95 in mesh with Worm wheel 96 on shaft 88. The respective worms-and wheels are so proportioned. as to effect a rotation of contact arm 89" once about its axis in every ten or fifteen seconds. This period of course maybe made of any desired length; but it is'desirable that it should not be too long in order to avoid possible waste of power. i

' The operation of the system is as follows:

Assuming that the transmission tubes are idle and that the valve 17 is closed. If now a carrier 97 be inserted into the open 'end of tube 1 at station A for despatch to station B, there will bean almost immediate slight rarefaction'of the air in tube 1 owing to the small flow of air which normally'occurs throughtube 1, conduit 7 tube 4, conduit 10, tube 11, conduit 32, by-pass 30 to the drum 12. This change in pressure may amount to, let us say, one-twentieth of announce per square inch, although it may be more orv considerably less depending on the length of tubes 1 and 4. Said slight change in pressure, however, is effective against the extended area. afiorded'by the walls of the breathing tube so thatslight as it is a sufiicient effortfwill beexerted, throughthe toggles 40, upon the rod 43fto lift plate 48 into engagement 'withthe contacts 50. It will be understood of course that at such time there will be no appreciable opposition to this elevation of rod43 owing to the fact that apparatus 44 is idle. The closure of circuit across contacts 50 results in themergization of solenoid 54in the manner above described. The core of the latter is thereupon lifted and engages contact bar 58 with contacts 59. This completes the circuit through the solenoid '29Qwhich raises the pilot valve 28 and the airadmitted to chamber 24 presses open the valve 17. v

Immediately there is. a: rush-of air into tube 1 'atits open end which conveys the carrier through this transmission tube toward terminal 2 atfivhich point itemerges,

opening valve 3 'as" it does so and thereby engaging switch 68 with contact 7 O, This completes a circuit through-wires 71' and 7 2 and, since switch 7 5' has previously been closed by the opening of valve 17 energizes solenoid 77 Thecore ofthe latter r'aises and in' so doing "opens valve 78 which throws the chamber in apparatus" 44 into communication with the drum l2 and ese tablishes a pressure which counteracts the tendency of the walls. 3 5-of 'the breathing tube to be prGSSfid in toward'each other by atmospheric "pressure resulting from I the relatively high vacuum existent withinthe breathing'tube at such time; valve 17 "being substantially wide open. If no carrier' is in course oftransit through either of the tubes the Contact 4 8 will then assume substantially its median position between contacts 49 and 50 which will Q of' course 'break circuit through the wire 55 and resultinthe deenergization of solenoid- 54. V H As long as a carrier is in'course of'transit, however, this balance cannot be effected since there Will be a slightly greater vacuum produced within the breathingtubelby reason ofthefpresence' of said fcarrier'in the transit. tube and this slight. difference in pressure in the apparatus 34 will be "sufiiicient to insure the maintenance ofplate 48 in engagement with contacts 50,1e Xceptunder the conditions now to be referred to. I

It may happen tliata carrier going from one station to another will have to traverse long vertical tube downwardly, in which case the speed-of descent of the carrier under the..action of. gravity may besufliciently at to ,even slightly compress the in ad'Vanceof'it. V 1 Und $1 9 ei e m ur e t e hr h :s jlenoid 29 will still normally be maintained since such fluctuation cannot be of long duration and the retarding device or dashpot in connection with solenoid 54 provides fer a possible interruption of the circuit ltiirough wire 55 of, let us say, one or two seconds.

hen, as aforesaid. the emergence of,a carrier at its point of delivery, completes the circuit which energizes solenoid 77 and ftliereupon imposes a counterbalancing eflort mpon the contact plate 48, were it not for "the provision of some means to maintain the valve 78 open for at least a period in excess of that allotted for the retardation of disengagement between contacts 58 and 59, the balancing eiiort would be removed from contact 48 before contact 58 had had an opportunity to descend out of engagement with contacts 59, and hence the valve 717 would be maintained open; but owing to the fact that valve 78 is latched up and is 'only released just as valve 17 is approaching its closed position, and further owing to the fact that valve 78 closes, when so released, at a rate determined by the adjustable valve 65 of its dash-pot, valve 28 will be closed, and thereafter the valve 17 will also be entirely closed just as this counterbalancing effort is completely removed, provided that said valve 65 be properly adjusted.

While it is possible to nicely adjust this release of valve 78 with respect to the closure of valve 17, I prefer to provide a dashpot acting diaphragm in connection with solenoid 77 similar to that described in connection with solenoid 54 and shown in Fig. 6, and this insures that the valve 78 shall not be fully closed or at least that the counteracting apparatus 44 shall not become inoperative until valve 17 has actually closed.

I am aware, however, that if valve 17 be flanged sufficiently as at 17 to cut off the flow of air therepast before-it reaches its seating position, the use of said dash-pot in connection with solenoid 77 may be avoided.

I may add here that the principal use of the dash-pot used in connection with solenoid 54 is to avoid unnecessarily numerous actuations of valve 28.

Returning, however,'to the description of the system as a whole, if there be a succeeding carrier in course of transit through, for example, tube 1, even despite the balancing effort exerted by apparatus 44, contact 48 will be in engagement normally with con tacts 50 or, for reasons aforesaid, with contacts 49 so that as long as a carrier is in course of transit through said tube, or indeed through either of the transit tubes, valve 17 will not be allowed to close.

Assuming now that a carrier is to be transmitted from station B to station Valve 6 will be opened and the carrier will be inserted at terminal 5whereupon the presence of said carrier (or if tube 1 be of suiiicient length, the mere opening of valve 6) will unbalance the equilibrium existing between the breathing tube apparatus and the sf ring 46 so that plate 48 will again be move into engagement either with contacts 50 or con- .tacts 49 and the valve '17 'will again be opened in the manner previously described and will be maintained open at least until said carrier encounters valve 9. The emergence of the carrier at station A effects the closure of a circuit at switch 67 and thereby again energizes solenoid 77 with results similar to those already discussed.

It will be observedthat if by any chance the system, merely operating as above described, should be started into operation and valve 17 be open when no carrier is in course of transit, as for example, if some one should cover the open end of tube 1 with the hand, or should insert a carrier and thereafter withdraw the same without leaving go of it, the valve 17 would thereafter remain open, there being no carrier in transit to effect a closure of the circuit at one or the other of the discharging terminals. I V

The intermittently actuating circuit maker in. casing 87 however, overcomes this difliculty since by reason of the continuous rotation of contact arm 88 the circuit will be periodically and intermittently established through wires 52 and 91 which will result in the periodic energization of solenoid 7 7 the same as if it had been energiied by the emergence of a carrier from a tu e. v

Hence if there be no carrier in course of transit there will in any case be a tendency periodically at determined intervals to es tablish the opposing effort which resists the increased pressure in the breathing tube due to the comparatively free connection be tween this apparatus and the drum when valve 17 is open, and therefore there will be a periodic tendency for contact 48 to move to its median position and to thereby eflect the closure of valve 17 in the manner above described.

It will thus be seen that I have provided a system in which the main air valve, or a corresponding device for controlling the establishment of a carrier transmitting flow of air throughthe transit tube, is rendered operative to so establish" said flow of air by the insertion of a carrier at a receiving terminal in the system, and that regardless of At the despatching terminal of station A is a casing 125 within which are contacts 126 to which are connected lead wires hereinafter referred to. In the path of a carrier being despatched from station A is a suitable contact making device 127 adapted to complete the circuit across the gap between contacts 126. From the contact 126 at station A there extends a wire 128 which connects with a wire 129 which leads downwardly to one of the contacts 109 previously referred to. Wire 129 may receive current from a positive lead 130.

From the lower of said contacts 126 extends a wire 131 which extends to a wire 132 which leads down tothe other of said contacts 109.

From wire 131 extends a wire 133 to solenoid 124 and a wire 134 leads therefrom to the magnet 107; a wire 135 connecting this latter with one of the contacts 111, and the other of said contacts 111 being directly connected to the negative lead 137. The valve 9 is provided with a switch 67 and contact 69, as in the previously described mechanism, and a wire 138 extends from the switch 67 to the wire 128. Similarly a connection 139 is provided between contact 69 and wire 123.

The valve 3 at station B corresponding to the similarly numbered valve in the first described mechanism, is in like manner provided with a switch 68 and contact 70; switch 68 being connected to the upwardly extending portion of the wire 132; and contact 70 being connected'by a wire 140 with the wire 129;

' 68 engaging contact 7 0 when said valve 6 is opened for the insertion of a carrier. The wire 132 extends directly to contact and wire 129, similarly, is connected to the pivoted switch 68.

The operation of this modification of my system is as follows:

Normally, valve 123 is closed and tubes 1 and 4 are dead; the air therein being at at mospheric pressure. As soon as a carrier is inserted at, for example, station A for despatch to station E, its forward end or head closes the circuit across the contacts 126by reason of its engagement with the resilient contact closer 127. Thereupon current flows from lead 130 via wire 129,'wire 128, contacts 126 and wire 133 to solenoid 124, energizing the latter and thereby opening the air inlet valve 123. The pressure of the atmosphere within drives'the carrier through tube 1 to station B, in a known manner. The electric current flowing from solenoid 124 passes via wire 134 through magnet 107 energizing the latter and thereby snapping contact plate 108 into engagement with contacts 109. The current traversing the coils of magnet 107 flows through wire 135 to the switch contacts 111 and thence out via the negative lead 137.

The engagement of plate 108 with contacts 109 establishes a maintaining circuit for magnet 107 and solenoid 124, since current can then flow from lead 130 down through wire 129 to contacts 109, and thence upwardly through wire 132 to wire 131 and through wire 133, solenoid 124, wire 134, magnet 107, wire 135, contacts 111 and lead 137 The space in the casing 115 below diaphragm 116 is in this construction preferably always in restricted communication with the drum 12, and hence said diaphragm will normally hold the catch 100 in its lowermost position, spring 117 aiding the partial vacuum below the diaphragm to this end.

Since the air in the transmission tubes 1 and 4 and in the exhaust conduit 111 is normally at atmospheric pressure and since the sensitive apparatus 34 is in communication with saidexhaust conduit, the apparatus 34 cannot oppose the downward positioning of catch 100 by said diaphragm and spring. As soon, however, as valve 123 is opened, a partial vacuum is created not only in the exhaust conduit 11 but also within the apparatus 34, the walls of which tend to collapse in the manner previously described. This action tends to raise-the rod 43 and thereby the catch 100 adjustably mounted thereon, 'but if no carrier be in course of transit through either of the transmission tubes the upward effort so exerted upon catch 100 will not be sufficient to overcome the combined downward effort exerted thereupon by the diaphragm 116 and spring 117 When a carrier has been inserted at, for example, station A, in the manner just described, a load will be thrown upon the current of air traversing the transmission tubes which will result in an increased rarefaction of the air in conduit 11. This in turn will correspondingly, but more gradually,

increase the vacuum in apparatus 34 and.

will enable said apparatus to lift catch 100 against the action of the diaphragm 11.6 and spring 117. The upward travel of catch 100 will be limited by the compression of spring 117, but under such conditions said catch will be disposed-above and clear of its latch 101, past which it will have snapped during the course of its upward movement.

Normally as long as any carrier is in course of transit through the system shown, catch 100 will be maintained above latch 101 by this increased vacuum in apparatus 34, but almost immediately after the emergence of said carrier at its destinatiomin the presthe transmission tubes.

out instance station B, provided there be no other carrier still in course of transit through either of the transmissiontubes, the vacuum in conduit 11 and shortly thereafter the vacuum in apparatus 341 will be that normally eXisting in these parts when valve 123 is open and the flow of air through the transmission tube is unrestrained.

hen such condition is reestablished the combined downward effort of diaphragm 116 and spring 117 will then be sufficient to Over come the upward effort exerted upon catch 100 by apparatus 34, and said catch will be moved down into engagement with its latch and will continue to move downwardly until, through the intermediacy of said latch and lever 102, circuit has been interrupted across contacts 111. The catch 100, as shown in Fig. 9, is just about to effect this breaking of circuit, but it will be observed that it is adapted for still further movement downwardly, which movement will not only break circuit at contacts 111 but will further driv the lower arm of the latch into engagement with the roller 114, whereupon said lower arm, acting as a cam, will rotate the latch clockwise and disengage it from the catch 100.

The interruption of the circuit at 111 deenergizes the magnet 107 and permits the lever 105 to drop," interrupting the maintaining circuit at 109 and at the same time deenergizing solenoid 124. The relatively heavy core of this solenoid thereupon closes the valve 123 and air ceases to flow through The several parts of the apparatus are now obviously all reset preparatory to the despatch of a second carrier from either station A or B.

The effect of mere fluctuations in pressure in conduit 11 will be minimized by the throttling of pipe 98, so that even if a long drop be present in the transmission line or tube, down which a carrier is descending and which carrier would tend to compress the air in advance thereof, by proper adjustment of valve 99 to meet such conditions in the system the apparatus 34 will not permit catch 100 to operatively engage its latch as a re.- sult of such momentary compression or partial reduction in rarefaction in the transmission tube ahead of said carrier. The emergence of a carrier through a valve 3 or 9 at a station, will of course, also cause such a momentary but ineffective change in pressure in conduit 11.

When thecarrier emerges from terminal 2, at station B it momentarily closes a branch of the maintaining circuit by the movement of switch 68 into engagement with contact 70, but since solenoid'124 is already energized the momentary closure of such branch will have practically no effect on the system. ,It sometimes happens, however, that a carrier sticks in the mouth of a faultily delivering terminal, holding the valve 3 open; and in such case wereit not for the provision of this branch circuit, sufficient air might be admitted to the tube 4 to permit catch 100 to drop and interrupt the maintaining circuit which would result in a closure of valve 123 while possibly some other carrier was in course of transit through tube 1;

Obviously, however, since the circuit is maintained closed at 6870 by the very carrier which is causing the trouble, the circuit cannot be 'so interrupted since even though catch 100 descends and breaks'circuit across contacts 111 momentarily, the circuit will immediately be closed again across these contacts and solenoid124 will be thereupon immediately reenergized. The following carrier wouldthen normally drive the carrier stuck in the mouth of terminal 2 out into the basket or receptacle and would then emerge itself, whereupon the system would automatically stop in the manner above described if no other carrier were in course of transit. It may also happen that some meddler may pull open the valves 3 or 9 by hand when a carrier is in course of transit or is being despatclied, but in such case this would not cause a permanent or even, at most, more than a momentary closure of valve 123. If a carrier be in'course of transit at such time its emergence will then close valve 123.

In despatching carriers from station B to station A, as soon as valve 6 is opened a short distance, the circuit will be immediately established and valve 123 will'open, so that even if the clerkwere dilatory in inserting a carrier to be despatched, no harm would result and any carrier in course of transit through tube 1 would continue on its way without material let or hindrance.

As a carrier approaching station A passes valve 9 the latter will of course be swung open and another branch of the circuit will be closed through switch 57 and contact 69 with the same effect upon" the systemas the engagement of switch 68 with contact 70. W

It will thus be seen that the system is substantially fool-proof and that with normal usage practically the utmost economy of power is effected by means of the construction showin V g I Having thus described my invention what I claim is:

1. A carrier despatch system comprising a way having a 'despatching and a receiving station for carriers, a source of powerf'or the transmission of carriers along said way, means for permitting a small expenditure of said power when said way isidle for the transmission of carriers, means for utilizing said smiall expenditure of power to automatically increase said expenditure for carrier transmitting purposes when a carrier is inserted at said despatching station, means to render nugatory the action of a part of said second mentioned means when the latter is subjected to the action of said increased power, and carrier controlled means to render said third mentioned means operative upon the arrival of a carrier at a determined point in its line of travel.

2. A carrier despatch system. comprising a way having a despatching and a receiving station for carriers, a source of power for the transmission of carriers along said way, means for permitting a small expenditure of said power when said way is idle for the transmission of carriers, means for utilizing said small expenditure of power to automatically increase said expenditure for carrier transmitting purposes when a carrier is inserted at said despatching station, means to render nugatory the action of a part of said second mentioned means when the latter is subjected to the action of said increased power, and means to render said third mentioned means operative upon the arrival of-a carrier at said receiving station.

3. A carrier despatch system comprising a way having a despatching and a receiving station for carriers, a source of power for the transmission of carriers along said way, means for permitting a small expenditure of said power when said way is idle for the transmission of carriers, means for utilizing said small expenditure of power to automatically increase said expenditure for carrier transmitting purposes when a carrier is inserted at said despatching station, means to render nugatory the action of a part of said second mentioned means when the latter is subjected to the action of said increased power, and means to render said third mentioned means operative under determined conditions in said system for a determined period of time, said last mentioned means including carrier controlled connections for rendering them operative upon the arrival of a carrier at a determined point in its line of travel.

4:. A carrier despatch system comprising a way having a despatching and a receiving station for carriers, a source of power for the transmission of carriers along said way, means for permitting a small expenditure of said power when said way is idle for the transmission of carriers, means for utilizing said small expenditure of power to automatically increase said expenditure for carrier transmitting purposes when a carrier is inserted at said despatching station, carrier controlled means to render nugatory the action of a part of said second mentioned means when the latter is subjected to the action of said increased power, and means to render said third mentioned means operative under determined conditions in said system, for an interval of time suflicient to enable the restoration of normal power expenditure conditions in said system when said way is again idle.

5. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined manner to establish a carrier propelling current of air through said conduit, a controlling device to act upon said means to automatically dis-establish said current of air thereafter, mechanism, controlled by the difi'erence in pressure in thewair in said conduit depending upon the presence or absence of a carrier in the path of the air current-in said conduit, means controlled by and coacting with said mechanism to normally prevent said device from so acting so long as a carrier is in course of transit through said conduit, and delaying means to prevent the current dis-establishing action of said device for an appreciable time after said pressure controlled means has been made subject to a pressure corresponding to that established when the conduit is free from carriers and the air current is flowing idly therethrough, whereby to prevent mere momentary fluctuations in pressure from causing a dis-establishment of said air current.

6. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined manner to establish a carrier propelling flow of air through said conduit, means tending to cause a dis-establishment of said flow of air thereafiter, a pressure-sensitive apparatus having pressure counter-acting provisions only through the action of which latter can said apparatus act responsively to the changes in pressure within said conduit resulting from the emergence of the last carrier in course of transit through said conduit, and means controlled by said apparatus for permitting said second mentioned means to effect a dis-establishment of said flow only after said last carrier has emerged.

7 A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined'manner to establish a carrier propelling flow of air through said conduit, means tending to cause a dis-establishment of said flow of air thereafter, a pressure-sensitive apparatus having pressure counter-acting provisions only through the action of which latter can said apparatus act responsively to the changes in pressure within said conduit resulting from the emergence of the last carrier in course of transit through said conduit,'means controlled by said apparatus for permitting said second mentioned means to effect a' dis-establishment of said flow onlya'fter said last carrier has emerged, and means for retarding the action of said second mentioned means.

8. A pneumatic d'espatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined manner to establish a carrier propelling flow of air through said conduit, a controlling element havmg a tendency to stop said fioW, pressure-sensitive mechanism responsive to the departure from a determined pressure in the flowing air resulting from the obstruction of-said-floW due to the presence of a carrier in said conduit, means controlled by said pressure-sensitive mechanism for preventing said element from acting to stop said flow until said pressure-sensitivemechanism permits of suchstoppage' following its subjection to said determined pressure, and means-to prevent mere momentary-fluctuations of pressure in said conduit from causing a stoppage of said flow through the action of said mechanism.

9. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined man ner to establish a carrierpropelling flow of air through said condu'it, a controlling element having a tendency to stop' said flow, pressuresensitive mechanism responsive to the departure from a determined pressure in the floivingvair resulting from'the ObSlil'llC tion of said flow due to the presence of a carrier in said conduit, means controlled by said pressure-sensitive mechanism for preventing said element fromacting' to stop said flow until said pressure-sensitive mechanism permits of such stoppage following its subjection to said determined pressure, and means td prevent mere momentary fluctua tions of pressure .in said conduit from causing a stoppage of said flow through the ac tion of said mechanism, said pressure-sensi tive. mechanism comprising a diaphragm Wall and counter-balancing provisions to oppose -movement of said ivall s'ufiioiently to render it sensitive to said departure in pressure in spite of said floiv of air through said conduit.

10. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined man'- ner to establish a carrier propelling How of air through said conduit and means to disestablishsaid flow of air thereafter, said disestablishing means acting dependently of the'change occasioned in said air by the emergence of a carrier from" said conduit When said air is unburdened by any second carrier in course of transit through said conduit, and comprising a pressure-sensitive apparatus having variably acting pressure counteracting provisions only through the action of which latter can said apparatus act responsively to said change, said provisions =being themselves responsive to changes in pressure in a determined part of said system. 7

11. A pneumatic despatch system com prising a transmission conduit having a des' patching and a receiving station-for carriers, means movable in a determined. man: ner to establish a carrier propelling flow of air through said conduit, means to dis-esta'blish said flow of air thereafter, said disestablishing means acting dependently of the change occasioned in said air by the emergence of a carrier from said conduit when said air is unburdened by any second carrier in course oftransit through said'conduit, and comprising a, pressure-sensitive apparatus having normally inoperative pressure counteracting provisions, means for rendering said pressure counteracting provisions operative at the emergence of a carrier at said receiving station.

12. A pneumatic despatch system comprising a transmission condu'ithaving a despatching and a receiving station for -carriers, meansmova'ble in a determined man-V ner to establish a carrier propelling fiOW of air through said conduit, means to discstablish said flow of air. thereafter, said disestablishing means acting dependently of the change occasioned in said air by the emergence of a carrierfrom said conduit when said air is unburdened by any second carrier in course of transit through said conduit, and comprising a pressure-sensitive. apparatus having normally inoperative pressure counteracting provisions, means for rendering said pressure counteracting. provisions operative at eachemergence of a carrier at said receiving station-and auxiliary means for rendering said pressure counteracting provisions operative at determined intervals of time. 7 V

13; Axpneumatic de'spatch system comprising a transmission conduit having a des patchingand a receiving station for carriers, means movable in a determined manner to establish a carrier propelling flow of air through said conduit, which air Will, in the absence of any carrier in said conduit; exert a determined pressure against the Walls of said conduit in a determined part of the latter, means to dis-establish said flow after said determined pressure is es-' tablished in said part of said conduit, auxiliary means for preventing said last mentioned means from soactmg so long-as any carrier whatsoever is in course of transit through said conduit, said a :;iliary means comprising an element mounted for movement in response to the change in pressure in said part of said conduit occasioned by the mere presence of the carrier in course of transit in combination with pressure counter balancing means for counteracting the effect on said element of said determined pressure, and means to prevent mere momentary fluctuations in said pressure from causing a stoppage of the air flow by said flow disestablishing means.

14. A pneumatic despatch system com prising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined manner to establish a carrier propelling flow of air through said conduit, means tending to act to dis-establish said flow Whenever a carrier emerges from said conduit at said receiving station, said last mentioned means including an electric circuit and a part in the path of said carrier adapted to be moved thereby to effect a change in said circuit, and means for preventing said change in said circuit from materially affecting said fioW of air so long as a second carrier is still in course of transit through said conduit.

15. A pneumatic despatch system comprising a transmission conduit having a des patching and a receiving station for carriers, means movable in a determined man ner to establish a carrier propelling flow of air through said conduit, means tending to act to dis-establish said flow Whenever a carrier emerges from said conduit at said receiving station, said last mentioned means including an electric circuit and a part in the path of said carrier adapted to be moved thereby to effect a change in said circuit, and means responsive to pressure changes in said system for preventing said change in said circuit from materially aifecting the flow of air through said conduit.

16. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, electrically operated means movable in a determined manner to establish a carrier propelling flow of air through said conduit, an electric circuit including contacts for controlling said means, contact actuating means tending to act on said circuit to dis-establish said flow, auxiliary means responsive to carrier induced departures from a determined pressure in a part of said system for preventing said lastmentioned means frcm so acting so long as the load of a carrier in course of transit through said conduit is imposed on said flow of air, and retarding means to provide a time interval following the establishment of said determined pressure in said part of the system to prevent mere momentary fluctuations from pern'iitting said contact actuating means to act to stop the air flow While a carrier is still in transit.

17. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, electrically operated means movable in a determined manner to establish a carrier propelling flow of air through said conduit, an electric circuit including contacts for controlling said means, means tending to act on said circuit to dis-establish said HOW of air, and means to co-act With the last carrier in course of transit through said conduit, for preventing said flow dis-establishing means from so acting until said last carrier has emerged from said conduit.

18. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined manner to establish a carrier propelling flow of air through said conduit, means tending to act to dis-establish said flow Whenever a carrier emerges from said conduit at said receiving station, means tending to act to dis-establish said flow of air at determined intervals, and auxiliary means for preventing either of said last mentioned means from so acting as long as any carrier is in course of transit through said conduit.

19. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined man ner to establish a carrier propelling flow of air through said conduit, means tending to act periodically to dis-establish said flow of air at determined intervals, and means for preventing said last mentioned means from so acting until the last carrier in course of transit through said conduit has emerged therefrom.

20. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined manner to establish a carrier propelling flow of air through said conduit, means tending to act to dis-establish said flow of air, means, responsive to pressure changes in said system, to co-act With the last carrier in course of transit through said conduit, to prevent said floiv-disestablishing means from so acting until after the lapse of a determined interval of time following the emergence of said carrier from said conduit, and means for determining the length oi said interval.

21. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined manner to establish a carrier propelling flow of air through said conduit, and means'i'or controllin said movable means including a device sensitive to slight departures from normal operative pressure conditions in said system, an electric circuit, electro magnetic means in said circuit having a movable part for controlling said movable means, said sensitive device adapted to make or break saidcircuit in accordance with said changes in pressure conditions in said system.

22. In an apparatus of the character described, transit tubing through which carriers are transmitted, air moving means for circulating air through said transittubing for propelling carriers, an air valve controlling the circulation of air through said.

transit tubing and normally closed, mechanism for operating said air controlling valve and adapted to be actuated to open said air controlling valve upon the despatch of a carrier or carriers to allow a circulation of air through said transit tubing for transmitting carriers, mechanism controlled by the circulating air in motion when said air controlling valve is open for retaining the said air controlling valve in an open position while a carrier or carriers are in transit and adapted to release said air controlling valve to allow it to return to its closed position after the last carrier discharge, mechanism for closing said air controlling valve, and means for regulating the closing of said air controlling valve after the discharge from said transit tubing of the last carrier in transit.

28. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means for maintaining normally a small flow of air through said conduit, means, sensitive to a relatively slight change in said small flow of air, for establishing a strong flow of air through said conduit for carrier transmitting purposes, and means, a part of which acts periodically for coi'interacting the effect upon said sensitive means of the changed pressure conditions in said system resulting from the establishment of a strong flow of air through said conduit.

24L A pneumatic despatch system comprising. a transmission conduit having a despat'ohing and a receiving station for carriers, means for maintaining normally a small flow of air through said conduit, means, sensitive to a relatively slight change in said small'flow of air, for establishing a strong flow of air through said conduit for carrier transmitting purposes, and means for counteracting the effect upon said sensitive means of the changed pressure conditions in said system resulting from the establishment of a strong flow of air through said conduit,

said last mentioned means including a periodically operative device and means for actuating said device.

25. A pneumatic despatch system com prising a transmission conduit having a despatching and a receiving station for carriers, means for maintaining normally a small flow of air through said con duit, means, sensitive to a relatively slight change in said small flow of air, for establishing a strong flow of air through saidconduit for carrier transmitting purposes, means, a portion of which is periodically acting, for counteracting the efi'ect upon said sensitive means of the changed pressure conditions in said system resulting from the establishment of a strong flow of air through said conduit,

and means for also counteractinn' aid effect upon the arrival of a carrier at said recciv ing station. I

26. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station, means for maintaining a carrier transmitting fio'w of air through said conduit so long as any carrier is in course. of transit therethrough, means, a part of which is at said receiving station and controlled by the delivery of a' carrier to said receiving station, for stopping said carr er transmitting flow of air if no other carrier is in course of transit through said conduit, and auxiliary means for automatically stopping the said flow of air in any case if said conduit is idle for carrier transmission purposes.

27. A pneumatic despatch system com? prising a transmission conduit having despatching and a receiving station for carriers,

a source of pneumatic pressure, means for permitting a small expenditure of' power from said source when said conduit is idle for thetransmission of carriers, means for utilizing this said small expenditure of power to automatically increase the expen diture of power from said source for carrier transmission purposes when a carrier is to be despatched to said receiving station, means to render nugatory the action o-f a part of said second mentioned means when the latter is subjected to the action of said increased power, and periodically acting means to render said third mentioned means operative. p p

28. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, a source of pneumaticpressure, means for permitting a small expenditure of power from said source when said conduitis idle.

for the transmission of carriers, means, sensitive to small variations in pressure, for utilizing this said small expenditure of power to automatically increase the expenditure of power from said source for carrier transmission purposes when a carrier is to be despatched to said receiving station, said greater expenditure of powertending to render said sensitive means insensitive and means to render nugatory the action of a part of said second mentioned means when the latter is subjected to the action of said increased power to resensitize said second mentioned means.

29. A pneumatic despatch system COli'lprising a transmission conduit having a des patching and a receiving station for carriers, a source of pneumatic pressure, means for permitting a small expenditure of power from said source when said conduit is idle for the transmission of carriers, means for utilizing this said small expenditure of power to automatically increase the expenditure of power from said source for carrier transmission purposes when a carrier is to be despatched to said receiving station, means to render nugatory the action of a part of said second mentioned means when the latter is subjected to the action of said increased power, and means to render said third mentioned means operative upon the arrival of a carrier at said receiving station.

30. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, a source of pneumatic pressure, means for permitting a small expenditure of power from said source when said conduit is idle for the transmission of carriers, means sensitive to small changes in pressure in said conduit for utilizing this said small expenditure of power to automatically increase the expenditure of power from said source for carrier transmission purposes when a carrier is to be despatched to said receiving station, means to render nugatory the action of a part of said second mentioned means when the latter is subjected to the action of said increased power to maintain said sensitive means adequately sensitive in spite of said increased expenditure of power, and means to render said third mentioned means operative under determined conditions in said system for an indeterminate period of time.

31. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, a source of pneumatic pressure, means for permitting a small expenditure of power from said source when said conduit is idle for the transmission of carriers, pressuresensitive means for utilizing said small expenditure of power to automatically increase the expenditure of power from said source for carrier transmission purposes when a carrier is to be despatched to said receiving station, counteracting means to inhibit the action of said increased expenditure upon said pressure-sensitive means to render said pressure-sensitive means sensitive under such changed conditions to the change in pressure thereon:resulting from the mere presence of a single carrier in the conduit, and means to render said third mentioned means operative under determined conditions in said system for an interval of time sufficient to enable the resto ation of normal power-expenditure conditions in said system when said conduit is again idle, said power increasing means co-acting with said counter-acting means to maintain uninterruptedly the increased expenditure of power during the transmission of any desired number of carriers each fol lowing the other through said conduit at in tervals sufficiently close to necessitate a continuing carrier transmitting flow of air through said conduit.

32. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, means movable in a determined manner to establish a carrier propelling flow of air through said conduit, means to dis-establish said flow of air thereafter, said dis-establishing means acting dependently of the change occasioned in said air by the emergence of a carrier from said conduit when said air is unburdened by any second carrier in course of transit through said conduit, and comprising a pressure-sensitive apparatus having normally inoperative pressure counteracting provisions, and means for rendering said pressure counteracting provisions operative.

33. A pneumatic despatch system comprising a transmission conduit having a despatching and a receiving station for carriers, a source of pneumatic pressure, means for permitting a small expenditure of power from said source when said conduit is idle for the transmission of carriers, means for utilizing this said small expenditure of power to automatically increase the expenditure of power from said source for carrier transmission purposes when a carrier is to be despatched to said receiving station, means to render nugatory the action of a part of said second mentioned means when the latter is subjected to the action of said increased power, and means to render said third mentioned means gradually inoperative upon the establishment of determined conditions in the system.

34,-. In a pneumatic despatch tube system, the combination of a transmission tube with a carrier and means for establishing a carrier propelling current of air through said tube, said carrier by its presence in said tube,

when in course of transit through the latter, 7

of contacts, for electrically controllingisaid air current establishing means, said icontacts When in a predetermined relationship to each other, causing a cessation of said air current, a device subject to changes in pressure of said air in said-part, for controlling the relationship of said contacts, said contacts being normally held out of said predetermined relationship when said air current has been once established so long as said departure from said pressure is maintained by a carrier, and retarding means to delay the setting of said contacts in their air current dis-estab1islring relationship even after said determined pressure in said part 1 is attained, to prevent mere momentary fluctuations of pressure in said tube from causing a cessation of said air. current.

In testimony whereof I have aflixed my signature, in the presence of two Witnesses. CHARLES P. HIDDEN. Witnesses: V

ISAAC KRASSEN, ETHEL M. JORDAN.

Copies of this patent may be obtained for five cents each, by agldressing the .rco mg li ssioner of Patents,

Washington, D. C. 

